Development of a resonant piezoelectric micro-jet for high-viscosity liquid using a longitudinal transducer

A resonant piezoelectric micro-jet (RPMJ) using a longitudinal transducer (LT) is proposed for achieving high-speed jetting of high-viscosity liquid. The continuous droplets are realized by the pressure change of micro-jet element (MJE) which can be generated by the high frequency vibration of the LT. The RPMJ is designed and its driving principle is simulated to reveal the pressure change and the jetting status. The modal and harmonic response analyses are performed to determine the resonant frequency of the LT. The transient and two-phase coupling analyses are launched to optimize the parameters of the MJE; and the jetting performances under the various viscosities of silicone oils are analyzed. A prototype of the RPMJ is fabricated and its tested system is established. The jetting of the silicone oil with the viscosity of 150 cps is achieved under the voltage of 300 V_p-p and frequency of 19.4 kHz, and the average flowrate is about 0.07 ml/s. The maximum average flowrate can reach to 0.51 ml/s when the viscosity is 2 cps. In a word, the viscosity range of operable liquid has been broadened using the proposed RPMJ.